Polymers of alkyl glycosides and process for preparing the same



Patented Aug. 8, 1-944 UNITED STATES PATENT OFFICE POLYMERS F ALKYLGLYCDSIDES AND PROCESS FOR PREPARING THE SAME Richard Seyfarth Schreiberand James Herbert Wemtz, Wilmington, Del., assignors to E, 1. du Pont deNemours & Company, Wilmington, DeL, a corporation of Delaware NoDrawing. Application July24, 1942, Serial No.- 452,134

Claims.

This invention relates to polymers of alkyl glycosides.

In the manufacture of regenerated cellulose film softeners are veryfrequently employed.

These must be water soluble but not migratory,

non-volatile, and compatible with the regenerated cellulose. Glyceroland ethylene glycol have been used for this purpose, but leave much tobe desired.

This invention has as an object new polymeric, water soluble materials.A further object includes new polymeric materials of low volatility andhigh compatibility with regenerated cellulose. Another object comprisesregenerated cellulose objects and particularly films containing assofteners therefor the new polymeric materials of this invention. Otherobjects will appear hereinafter.

These objects are accomplished by the following invention of apolymerization process wherein a monomeric alkyl glycoside ispolymerized by heating, under substantially anhydrous conditions, withan acidic catalyst to yield a water soluble polyglycoside whichpolyglycoside may be used as a softener for regenerated cellulose film.

By substantially anhydrous conditions is meant that the reactionmixture'contains no more than traces ofwater, i. e., not more than 1%.

In carrying out the process of this invention an alkly glycoside ismixed with less than 1% by weight-of an acidic catalyst such as sulfurica rid, iodine, or a trialkylsulfonium iodide and the r ixture is thenheated at 150-200 C. for several hours preferably under an inertatmosphere either at atmospheric or reduced pressures. During thisheating period the alcohol corresponding to that used-= in thepreparatioiixgof the monomeric glycoside is evolved with subsequentincrease in the viscosity of the melt. The resulting syntheticpolyglycosides are clear, transparent, glassy,

brittle solids which are stilloptically active and" soluble in water andalcohol, but insoluble in acetone. a

The more detailed practice of the invention is illustrated by thefollowing examples, wherein parts given are by weight. There are ofcourse many forms of the invention other than these specificembodiments.

Example I Ten parts of alpha-methylglucoside was melted under nitrogenat 180 C. at atmospheric pressure which resulted in a clear light amberfluid. To this solution were added a. few crystals ofdodecyldimethylsulfonium iodide. Immediately after the addition of thiscatalyst there was a steady evolution of bubbles indicating theformation of a distillate which was found to be methanol. The viscosityof the solution increased during the course of 30 minutes and at the endof this time a vacuum of 3 mm. was applied for an additional 20 minutes.The viscous, amber fluid was allowed to cool at room temperatureresulting in a transparent, amber, brittle, glassy solid which wassoluble in water, alcohol and acetic acid, but insoluble in acetone anddioxane and gradually meltd over the range of 59-93 C. Molecular weightdeterminations run in acetic acid gave a.

' value of 380 indicating the condensation of' about rotation of 3 unitsof methyl glucoside.

Example If Twenty parts of alpha-methylglycoside was treated with 0.01part of diethylmethylsulfonium iodide catalyst and the mixture heated to180 C. during which time the alpha-methylglucoside liquefied. At thistemperature the melt appeared to darken somewhat and at the same timebecame increasingly more viscous. At the end of 15 minutes heating wasdiscontinued and the transparent, brown, glassy solid which resulted wasfound to have a softening point of C.

and a molecular weight of 455 as determined by freezing point depressionin water. This product was found to be optically active having aspecific and to be readily soluble in acetone.

Example III methods gave a value of 729, indicating that this materialwas composed of 4 5 methylglucoside units.

7 Example!!! Fifty parts 'of alpha-methylglucoside was treated with0.0054 of sulfuric acid dissolved in 0.2 part of methanol.'lhismixturewas heated at 180 C. for 1% hours during which time 8.3parts of liquid was evolved. This liquid was analyzed and found to bepractically pure methanol. The light amber solid which resulted had amelting point of 210 C. and was soluble in methanol and water, butinsoluble in acetone.

The methoxyl content. was found to be 3.6% indicating a molecular weightof 861 or slightly more than five glucoside. units.

Example V Two hundred parts of alpha-methylglucoside and about 8 partsof a methanol solution containing about 0.000912 part of borontrifiuoride were heated one hour at l'70 180 C. The product was a hard,clear, glass-likeresin.

Example VII Fifty parts of alpha-methylglucoside was heated with 0.0054part of sulfuric acid dissolved in 0.2 part of methanol at 180 C. for 2/2 hours,

during which time methanol was evolved. The

resulting viscous, am'ber liquid was allowed to cool, giving a glassy,brittle polymer having a melting point above 200 C. which was soluble inmethanol and water but insoluble in acetone.

The methoxyl content was found to be 1.71%

which indicates a .molecular weight of 1812 or approximately 11glucosidic units.

While any monomeric alkyl glycoside may be employed in the process ofthis invention to prepare water soluble polymeric glycosides, it ispreferred that the glycosides be those of alcohols of low molecularweight, e. g., methylglyc'osides, ethylene glycol, glycerol, sorbitol,l-dodecylthiosides, amylglycosides and hexylglycosides, i. e., anyglycoside of an alkanol of from one to six carbon atoms including notonly alkyl glyoscides of glucose, but also those of monosaccharides ingeneral including those of arabinose, ribose, xylose, galactose,fructose, threose, rhamnose, glycerose, and mannose. Mono, di, and trisub-, stituted ethers or esters of alkyl glycoside are also applicable,for example, triacetyl methylglucoside, ethyl methylglucoside, andacetyl methylglucoside.

In the process of this invention, any acidic catalyst may be employed.However, those acidic catalysts are preferred which are strong acids,

or render available a strong acid under the conditions of the reaction,such as sulfuric acid, dimethyl sulfate, iodine, trialkylsulfoniumiodides, such as dodecyldimethylsulfonium iodide andethyldimethylsulfonium iodide, ammonium chloride, piperidinehydrochloride, hexadecylpyridinium bromide, and boron trifluoride; Bythe term "strong acid is meant acids having an ionization constantgreater than 1X10- While any amount of catalyst may be employed, the useof excessive amounts, 1. e., above 1%, based on the weight of the alkylglycoside, frequently results in some degradation of the alkyl glycosideand also in an excessively rapid and even explosive reaction. [As low as0.001% of catalyst may be employed.

\ tially insoluble in dioxane.

Temperatures ranging from room temperature 7 up to 300 C. can beemployed successfully for the conversion of alkyl glycosides towater-soluble polymers. In order to avoid the formation of a coloredproduct and to obtain high molecular weight materials, it is preferredto work in the range of -225 C. However, the temperature employeddepends somewhat on the glycoside which is to be polymerized. In mostcases it is preferred to heat the glycoside and catalyst to thattemperature at which the glycoside is in a molten condition and at whichpoint there is a continual evolution of alcohol.

The term required for carrying out polymerization of this type rangesfrom a few minutes to several hours depending on the temperature,catalyst and glycoside employed. The polymerization is carried tocompletion in shorter time at higher temperature or at the sametemperature with increased amount of catalyst. The higheralkylglycosides polymerize more slowly than the lower alkylglycosides,e. g., methylglucoside. Completion of reaction is marked by cessation ofalcohol evolution and of viscosity increase. In general 1-3 hours isnecessary to obtain polymers having maximum molecular weights.

While it is preferred to carry out this reaction in the absence of asolvent, inert solvents such as dioxane may be used.

By conducting the polymerization of the alkyl glycoside in the presenceof a polyhydric alcohol or a polyhydroxythiol, preferably boiling aboveC., modified polymers are obtained in which the and group comprises thesaid alcohol or mercaptan radical. Examples of such reagents areethylene glycol, glycerol, sorbitol, l-dodecylthiosorbitol,monothioglycerol, l-thiosorbitol, and the polyethylene glycols. As inthe case of methyl glycoside polymers in which the methoxyl end groupplays such an important part in imparting improved thermo stability,wider range of solubility properties, and greater resistance to catalystdegradation, these polyfunctional end grouping agents generally tend toaccentuate these properties.

Certain agents such as polyalkoxymethyl substituted amides which inthemselves are capable of resinification in the presence of acidcatalysts can be copolymerized with alkyl glycosides to yield noveltypes of water soluble copolymers. Compounds of this .class include theN,N'-bis(alkoxymethyl) ureas, such as N,N'-bis(methoxymethyl) urea, N,N'-bis(ethoxymethyl) urea, N,N'-bis (isobutoxymethyDurea; theN,N'-bis(alkoxymethyllurons, such as N,N'-bis(rnethoxymethyl) uron,N-N'-bis(ethoxymethyl)uron and N,N'-bis(butoxymethyl) uron; theN,N',N"-trisalkoxymeth yDmeIamines, such as N,N',N"-tris(methoxymethyl)melamine, N,N',N"-tris (propoxymethyl) melamine and N,N',N' '-tris(isobutoxymethyl) melamine; and the N,N'-bis(alkoxymethyl) substitutedamides of dicarboxylic acids, such as adipic and sebacic acids. Thepreferred compounds of this class are N,N-bis(methoxymeth- .yl)adipamide and N,N'-bis(ethoxymethyl) adipamide. Other compounds whicharecapable of copolymerization with-alkyl glycosides are the cyclic acetalssuch as dioxolane. These cyclic acetals are obtainable from simplealdehydes and glycols. These copolymers are water soluble and range fromviscous sirups to hard glassy resinOI-ll materials.

The products of the invention, including the copolymers, while solublein water are substan- They are characterized, inter alia, in that theyhave an alkoxy 'hyde or ketone carbonyl carbon).

group, preferably of from one to six carbon atoms on the oxocarbonylicor ketaldonyl carbon (alde- Although products having molecular weightscorresponding to dimers, trimers and tetramers of the alkyl glycosidesare useful those having molecular weights greater than 1000 are morevaluable. However, polymers of as low molecular weight as 400 areincluded in this invention.

The products of this invention are particularly suitable as softenersfor regenerated cellulose films, as textile printing assistants, and asnonionic wetting agents.

The above description and examples are intended to be illustrative only.Any modification of or variation therefrom which conforms to the .spiritof the invention is intended to be included within the scope of theclaims.

What is claimed is: 1. Process of preparing polymers which com- 4.Process of preparing polymers which comprises heating, under anhydrousconditions at a temperature within the range 100-225 0., a compositioncomprising essentlally an alkyl glycoside and an acidic catalyst,removing the alcohol as it is formed and discontinuing the heating whenthe evolution of alcohol substantially ceases.

5. Process of preparing polymers which comprises heating, underanhydrous conditions at a temperature within the range 100-225 C., acomposition comprising essentially a lower allryl glycoside and anacidic catalyst, removing the alcohol as it is formed and discontinuingthe heating when the evolution of alcohol substantially ceases.

6. Process of preparing polymers which comprises heating, underanhydrous conditions at a temperature within the range 100-225 0., a

prises heating, under substantially anhydrous conditions,alpha-methylglucoside at a temperature within the range 100-225 C. inthe presence of an acidic catalyst, removin the alcohol as it is formedand discontinulngthe heating when evolution of alcohol substantiallyceases.

2. Process of preparing polymers which comprises heating, underanhydrous conditions a lower alkyl glycoside at a temperature within therange 100-225 C. in the presence of an acidic catalyst, removing thealcohol as it is formed and discontinuing the heating when alcoholevolution substantially ceases.

3. Process of preparing polymers which com-' prises heating, underanhydrous conditions an alkyl glycoside ata temperature within the range100-225" C. in the presence of an acidic catalyst, removing the alcoholas it is formed and discontinuing the heating when alcohol evolution. 0

substantially ceases.

composition comprising essentially alpha methyl-glycoside and an acidiccatalyst, removing the methanol as it is formed and discontinuing theheating when the evolution of metha-- nol substantially ceases.

'l. A water soluble high molecular weight condensation polymer of analkyl glycoside.

8. A water soluble high molecular weight condensation polymer of a loweralkyl glycoside.

9. A water soluble high molecular weight condensation polymer ofalpha-methylglucoside.

10. Process of preparing polymers which.comprises heating, underanhydrous conditions at a temperature within the range -225" C., acomposition comprising essentially a l p h a methylglycoside anddodecyldimethyl-sulfonium iodide, removing the methanol as it is formedand discontinuing the heating when the evolution of methanolsubstantially ceases. v

RICHARD SEYFARTH SCHREIBER. JAMES HERBERT WERNTZ.

CERTIFICATE OF CORRECTION;

PatentNo. 2,-.555',2 L5. August 8', 19M" RIcHARD-S FARTH 'SCHREIBER, ETAL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 2,first column, line 11+; after the word "coo-ling" insert a c onnna; lineM4, strike t "ethylene e y glycerol, sorhitol, l-dodecylthio and insertinstead ethylglycosides, butylglycosides, isobutylglyco and secondcolumn, line 13, for "-term" read --time-; and that the'said LettersPatent should beread with this correction therein that the same mayconform to the record of the case in the Patent Office. I

Signed-and sealed this 26th day of September, A. D. 19%.

Leslie Frazer (Seal) Acting'commissioner of Patents.

